This invention relates to the field of marine vehicles or ships that are at least partially supported by submerged structures that are sometimes known as lifting bodies. These submerged structures may take any of a number of forms with a hydrofoil shape preferred. The submerged structure(s) is normally connected to an above water hull portion of the ship by a strut-like member(s). This invention also extends into the fields of air lubricated boat hulls and boundary layer control means to improve hull and/or propulsor efficiencies.
Applicant has pursued Surface Effect Ship (SES) technology for a number of years as is evidenced by numerous United States patents. A typical example is Burg, U.S. Pat. No. 5,860,380. It is important to note that the SES rides on the top of the water when moving forward at cruise or high speeds while the instant invention does not. For purposes of this application, high speed is defined as speeds of 15 knots or more. The prior art is exemplified as being a surface skimming SES design by noting the static waterline and the high speed dynamic waterline, A and C respectively, in that Burg patent. Contrarily, the supporting structure is, at least in its majority, submerged during both static and high speed operation in the instant invention""s case.
Air lubrication, with the air supplied by artificial pressurization means, is employed in the preferred embodiment of the instant invention to reduce wetted area of the underside of the submerged structure(s). It is important to note that a portion of the submerged structure(s) forward of the air injection is rather deep in the water to thereby dig a deep hole in the water forward of the air layer. This is therefore classed as a true air lubrication system and not a SES.
In its preferred embodiment where the submerged structure(s) is hydrofoil shaped, at least on its upper surfaces, added lift is possible by controlling the boundary layer. This is done by taking in water for the propulsor(s) from the upper surfaces of the submerged structure(s) at selected location(s). An added benefit of taking in this boundary layer is that the propulsor are rendered more efficient due to the added momentum change to the water imparted by the propulsors. Yet another benefit is that the propulsors are not subject to taking in aerated water since they are operating distal from the air layer(s).
The instant invention offers advancements over applicant""s earlier inventions as well as over the prior art. These advancements are discussed in detail in the following sections.
The object of the instant invention is to offer the tremendous stability of a marine vehicle hull connected to a first submerged structure by way of one or more connecting structural member(s) but with higher efficiencies than are normally associated with such designs.
It is a directly related object of the invention that the first submerged structure be, at least in its majority, submerged during high-speed operation of the marine vehicle.
It is a related object of the preferred embodiment of the invention that the connecting structural member(s) be strut-like in shape.
A related object of the invention is that such connecting structural members, in their preferred embodiment, be at least in part airfoil shaped.
It yet another object of the invention that there be means to supply pressurized gas from artificial gas pressurization means to an underside of said first submerged supporting structure to thereby form a friction reducing gas layer.
A directly related object of the invention is that the gas layer, on average, rises going from forward to aft.
A further related object of the invention that the gas layer be formed, at least in its majority, aft of a discontinuity in a lower surface of the first submerged supporting structure.
Yet another object of the invention is that port and starboard portions of said gas layer can be, at least in their majority, separated by structure.
It is a directly related object of the invention that the structure separating port and starboard portions of the gas layer be as a keel proximal the centerline of the marine vehicle.
Another related object of the invention is that the gas layer be restrained by a sidekeel of said first submerged supporting structure.
Another object of the invention is that the first submerged supporting structure be, at least in part, airfoil shaped.
It is a related object of the invention that a forward outermost portion of the first submerged supporting structure be aft of a forward portion proximal the horizontal centerline of the submerged supporting structure.
It is a further related object of the invention that a submerged supporting structure be comprised of port and starboard airfoil shapes that converge going inward toward each other.
Yet another object of the invention is that there be a propulsor that takes in water from a location proximal an upper surface of a submerged supporting structure.
A directly related object of the invention is that, during high speed forward operation in calm seas, at least twenty percent of the water taken into the propulsor be from a boundary layer adjacent a submerged supporting structure.
Another directly related object of the invention is that, during high speed forward operation in calm seas, at least thirty percent of the water taken into the propulsor be from a boundary layer adjacent a submerged supporting structure.
Yet another directly related object of the invention is that, during high speed forward operation in calm seas, at least forty percent of the water taken into the propulsor be from a boundary layer adjacent a submerged supporting structure.
Still another directly related object of the invention is that, during high speed forward operation in calm seas, at least fifty percent of the water taken into the propulsor be from a boundary layer adjacent a submerged supporting structure.
A further object of the invention is that a control surface be disposed proximal a submerged supporting structure.
A directly related object of the invention is that the control surface be a flap like member.
Another object of the invention is that is may include a second submerged supporting structure.
A related object of the invention is that one of the supporting structures can be, on average, higher than the other.
It is a directly related object of the invention that the aft supporting structure be higher than the forward supporting structure.
Another object of the invention is that at least one of the connecting structural members be, at least in part, airfoil shaped.
Yet another object of the invention is that a connecting structural member include a pressurized gas passageway that is in gaseous communication with the artificial gas pressurization means and the gas layer.